Slightly above your budget but these are a great pair of earphones. I bought the black version for £30 a while ago but are £22.99 delivered now. Link
There is also a very similar looking but cheaper pair for £9.99. Link

Slightly above your budget but these are a great pair of earphones. I bought the black version for £30 a while ago but are £22.99 delivered now. Link
There is also a very similar looking but cheaper pair for £9.99. Link

Never used them personnally but are mentioned a lot on here. Is this the website with the really expensive P&P? Amazon undercut Play.com and have them for about £16.95 with super saver delivery thats all in.

There are so many sennheiser fakes out there, only buy them from a well regarded store. I got my CX500s from Play.com and they are brilliant. This is after getting a fake pair on ebay from a powerseller with 97.6% positive feedback. A lesson learned on my part.